linux-kernel - [PATCH] x86/AMD: Fix Socket ID for LLC topology for AMD Fam17h systems

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Date:   Wed, 31 Aug 2016 15:21:40 -0500
From:   Yazen Ghannam <Yazen.Ghannam@....com>
To:     <tglx@...utronix.de>, <mingo@...hat.com>, <hpa@...or.com>,
        <x86@...nel.org>
CC:     <linux-kernel@...r.kernel.org>,
        Yazen Ghannam <Yazen.Ghannam@....com>
Subject: [PATCH] x86/AMD: Fix Socket ID for LLC topology for AMD Fam17h systems

The Socket ID is ApicId[bits] on Fam17h systems.

Change substraction to logical AND when extracting socket_id
from c->apicid.

Signed-off-by: Yazen Ghannam <Yazen.Ghannam@....com>
---
 arch/x86/kernel/cpu/amd.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index f5c69d8..479555f 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -365,7 +365,7 @@ static void amd_detect_cmp(struct cpuinfo_x86 *c)
 	 if (c->x86 != 0x17 || !cpuid_edx(0x80000006))
 		return;
 
-	socket_id	= (c->apicid >> bits) - 1;
+	socket_id	= (c->apicid >> bits) & 1;
 	core_complex_id	= (c->apicid & ((1 << bits) - 1)) >> 3;
 
 	per_cpu(cpu_llc_id, cpu) = (socket_id << 3) | core_complex_id;
-- 
1.9.1